Contents

Print every region once

To print each region we must create our own list
regionList.
As we process each country we add the region to our list. The
value we put in does not matter, we can use anything. Some regions
will be added many times - this doesn't matter each simply over-writes
the previous.

There are two loops in the code. In the first loop we go over every country in the structure world which has been given.
The second loop goes over the structure created.
Initially the first loop simply prints each region. Instead it
should add the region to regionList.